An open-end or monkey wrench includes two jaws for contact with two facets of a nut so that the nut can be driven with the wrench. The corners of the nut might however be chamfered due to forces exerted thereon when the wrench is used improperly. In an attempt to solve this problem, as disclosed in U.S. Pat. No. 4,838,132, a monkey wrench is provided with two jaws for contact with the middle points of two of the facets of a nut. The corners might nevertheless be chamfered with the monkey wrench.
Therefore, the present invention is intended to obviate or at least alleviate the problems encountered in prior art.